Heart Attack vs. Cardiac Arrest: Understanding the Critical Differences

Learn how heart attacks and cardiac arrest differ, including symptoms, causes, emergency response, and prevention for each life-threatening condition.

By Medha deb

Created on Sep 26, 2025

Learn how heart attacks and cardiac arrest differ, including symptoms, causes, emergency response, and prevention for each life-threatening condition.

Heart attacks and cardiac arrest are both life-threatening emergencies that affect the heart, but they are distinct events with unique causes, symptoms, and treatments. Misunderstanding these terms can delay proper response and worsen outcomes. This comprehensive guide will clarify the differences and connections between these conditions, detail their signs and risk factors, and outline how to respond and reduce your risk.

Overview: Are Heart Attack and Cardiac Arrest the Same?

While the terms “heart attack” and “cardiac arrest” are often used interchangeably, they represent two separate medical emergencies:

Heart attack (myocardial infarction): Caused by a blockage that prevents blood from reaching part of the heart, leading to tissue damage .
Cardiac arrest: An abrupt loss of heart function due to an electrical malfunction, causing the heart to stop effectively pumping blood .

Although they are different, a heart attack can sometimes lead to cardiac arrest, and both require immediate medical attention .

Key Differences: Heart Attack vs. Cardiac Arrest

	Heart Attack	Cardiac Arrest
Primary Issue	Blood flow blockage (circulation problem)	Electrical malfunction (electrical problem)
Onset	May develop over minutes or hours; symptoms can be gradual or sudden	Usually sudden and unexpected; immediate collapse
Main Symptoms	Chest pain, shortness of breath, fatigue, nausea	Loss of consciousness, no pulse, no breathing
Heart Beat	Usually continues beating	Stops beating effectively
Treatment	Restore blood flow (medications, stents, surgery)	CPR, defibrillation, emergency care

What Is a Heart Attack?

A heart attack occurs when one or more arteries supplying blood to the heart muscle become blocked, usually by a build-up of plaque or a blood clot. Without sufficient oxygen, the affected heart tissue begins to die. The longer the blockage persists, the greater the damage .

Common Causes

Coronary artery disease (most frequent cause)
Blood clots forming in the arteries
Plaque build-up (atherosclerosis)
Coronary artery spasm (rare)

Symptoms

Symptoms can range from mild to severe, may develop gradually, and sometimes go unnoticed. Not everyone experiences all symptoms, and women’s symptoms can differ from men’s. The most common signs include:

Chest pain or discomfort (may feel like pressure, squeezing, or fullness)
Pain that radiates to arms, neck, jaw, back, or stomach
Shortness of breath
Cold sweat
Nausea or vomiting
Fatigue or dizziness

The heart usually does not stop beating during a heart attack. Some people have mild symptoms or none at all (silent heart attack).

What Is Cardiac Arrest?

Cardiac arrest is a sudden loss of heart function due to a malfunction in the heart’s electrical system. This causes the heart to stop beating effectively (ventricular fibrillation or tachycardia are common causes), cutting off blood supply to the brain and vital organs. Cardiac arrest can be fatal within minutes if not treated immediately .

Common Causes

Abnormal heart rhythms (arrhythmias), especially ventricular fibrillation
Heart attack (most common trigger)
Certain heart conditions (e.g., cardiomyopathy, congenital heart disease)
Severe blood loss or oxygen deprivation
Electrolyte imbalances
Severe trauma

Symptoms

Sudden collapse
No pulse
No breathing
Loss of consciousness

Cardiac arrest often occurs with no warning and can be mistaken for fainting. Without rapid intervention, it usually leads to death within minutes .

How Heart Attack and Cardiac Arrest Are Related

While they are distinct, heart attacks and cardiac arrest can be connected:

Heart attacks are a major cause of cardiac arrest. The damage from a heart attack can trigger life-threatening arrhythmias that lead to cardiac arrest.
During or shortly after a heart attack, the risk of cardiac arrest increases.
Both share many risk factors (e.g., age, smoking, high blood pressure, diabetes, family history).

However, not all cardiac arrests are caused by heart attacks, and not all heart attacks lead to cardiac arrest .

Which Is More Dangerous: Heart Attack or Cardiac Arrest?

Both conditions are medical emergencies, but cardiac arrest is often more immediately life-threatening. Cardiac arrest causes a complete halt in heart function, leading to loss of consciousness and absence of breathing or pulse. Without immediate treatment (CPR/defibrillation), death can occur within minutes.

Heart attacks are serious but may allow more time to seek help as the heart continues to beat, though delayed treatment can still lead to severe complications or cardiac arrest .

Recognizing Symptoms: How to Tell the Difference

Heart Attack:

Gradual or sudden chest pain/pressure
Radiating pain (shoulders, arms, jaw, back)
Shortness of breath
Possible cold sweat, nausea, or faintness

Cardiac Arrest:

Sudden collapse
No response
No pulse or breathing
Often occurs without warning

In both cases, call emergency services (911) immediately.

What to Do in an Emergency

For a Suspected Heart Attack

Call emergency services right away.
Keep the person calm and seated or lying down.
If aspirin is available and not contraindicated, offer one to chew (as advised by emergency responders).
Monitor breathing and pulse until help arrives.

For Cardiac Arrest

Call emergency services immediately.
Check for a pulse and breathing.
Begin CPR right away (push hard and fast in the center of the chest).
If available, use an Automated External Defibrillator (AED) as soon as possible.
Continue CPR and AED use until emergency personnel arrive.

Risk Factors: Who Is at Greatest Risk?

Common risk factors for both:

Older age
Family history of heart disease
High blood pressure
High cholesterol
Diabetes
Smoking
Lack of physical activity
Obesity

Specific triggers for cardiac arrest: Congenital heart defects, previous arrhythmias, certain medical conditions, or severe trauma.
Specific triggers for heart attack: Existing artery disease, atherosclerosis, or acute clot formation.

Prevention Strategies

Adopt a heart-healthy lifestyle:

Eat a balanced, low-sodium, low-saturated-fat diet
Maintain healthy weight
Exercise regularly
Avoid tobacco use and excessive alcohol
Manage stress

Control chronic conditions like high blood pressure, high cholesterol, and diabetes through regular checkups and medication as prescribed.
Know your family history and discuss any risk factors with your healthcare provider.
If at elevated risk, consider discussing screening for arrhythmias or heart disease with your physician.
Learn CPR and how to use an AED—these skills can save lives in a cardiac emergency.

Frequently Asked Questions (FAQs)

Is cardiac arrest always fatal?

Not always, but cardiac arrest can be fatal within minutes if not treated immediately with CPR and defibrillation. Rapid response greatly increases survival odds.

Can a heart attack cause cardiac arrest?

Yes, a heart attack can disrupt the heart’s electrical system and trigger a fatal arrhythmia leading to cardiac arrest, especially during or in the immediate aftermath of a heart attack.

Do all heart attacks have chest pain?

No. While chest pain is common, some heart attacks have only mild symptoms, or none at all. Symptoms are sometimes more subtle in women, older adults, and people with diabetes.

Can young, healthy people have cardiac arrest?

Yes. While most victims are older adults with preexisting heart conditions, cardiac arrest can occur in young and healthy people, especially those with undiagnosed heart abnormalities or due to trauma, drug use, or extreme physical exertion.

How can I tell if someone is having a heart attack or cardiac arrest?

People in cardiac arrest are unconscious, unresponsive, not breathing, and have no pulse—immediate CPR is needed. People having a heart attack are usually conscious and may complain of chest pain, nausea, or difficulty breathing. In both cases, call emergency services right away.

Are there lasting effects after surviving a heart attack or cardiac arrest?

Yes. Surviving a heart attack can leave damaged heart tissue and may increase the risk for future heart problems, including arrhythmias or heart failure. Survivors of cardiac arrest can have neurological damage if the brain has been deprived of oxygen, depending on how quickly blood flow was restored.

Key Takeaways

Heart attack is a blockage in a coronary artery that damages heart muscle but often leaves the heart still beating.
Cardiac arrest is a sudden failure of the heart’s electrical system that stops the heart from pumping blood.
Heart attacks can lead to cardiac arrest, but the two require different emergency responses.
Quick recognition and action—calling 911, starting CPR, and using an AED—save lives.
Managing heart health and knowing the risks can reduce the chance of both conditions.

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

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